Combination blackboard chalk and eraser

ABSTRACT

A combined blackboard chalk and eraser in which the chalk is provided with an embedded eye to permit the chalk to be attached to a cord and suspended from the top of the blackboard. The chalk has an eraser element secured to one end thereof so that the board can be erased, using the chalk as a handle for the eraser.

I Umted States Patent [151 3,656,201 Alcocer [451 Apr. 18, 1972 [54] COMBINATION BLACKBOARD CHALK 3,257,679 6/1966 Duskins ..15/118 AND ERASER 3,418,673 12/1968 Kruth ..15/118 [72] Inventor: Francisco 0. Alcocer, Calle Arista 835, FOREIGN PATENTS OR APPLICATIONS 616,440 2/1927 France ..401/52 [22] Filed: Dec. 12, 1969 702,323 1/1931 France.....

1,003,088 11/1951 France [21] 884503 84,306 2/1957 Netherlands ..401/52 [52] US. Cl ..15/118, 264/274, 401/ 1 31 Primary Examiner-Daniel Blum [51] Int. Cl. ..B43k 29/02, 1343121/00 Attorney-Kimmel, Crowell & Weaver [58] Field of Search ..15/105, 118, 104.93, 104.94,

15/105.51; 401/6, 8, 49, 52, 131; 35/67 [57] ABSTRACT A combined blackboard chalk and eraser in which the chalk is [56] References cued provided with an embedded eye to permit the chalk to be 111- UNITED STATES PATENTS tached to a cord and suspended from the top of the blackboard. The chalk has an eraser element secured to one 1,750,912 Towne X end thereof so the board can be erased using the as 2,] 8C0 1 X a handle for [he erasen 1,103,955 7/1914 Garon ....401/131 X 2,086,174 7/1937 Rutz 35/67 X 1 Claims, 4 Drawing Figures Pmmm 18 m I INVENTOR I 0. flLCQQ/P,

e1 M g ATTORNEYS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to blackboard chalks and erasers and more particularly to a combined blackboard chalk and eraser such as to keep the eraser always available with the chalk.

2. Description of the Prior Art It is now a normal procedure to make blackboard chalks out of calcareous or gypsum materials, in the shape of small cylinders of approximately five-sixteenth inch diameter by 3 inches long. Such chalks leave a legible line of chalk upon the dark background of the blackboard which can be easily wiped off afterwards in order to clean the surface of the backboard for other use.

To clean the blackboard it is a general procedure to wipe it with a rag or a piece of cloth or felt affixed to a wooden handle. However it happens often that such a conventional eraser is misplaced and people using the blackboard are reduced to searching for the eraser even when only a minor error needs to be erased.

SUMMARY OF THE INVENTION The present invention provides a chalk member having a size somewhat greater than conventional chalk and provided with an eye for attaching a string to suspend the chalk from the top of the blackboard. The chalk is further provided with an eraser element secured to one end thereof so as to make the eraser available for the correction of minor errors whenever the chalk is in use.

The primary object of the invention is to provide a combined eraser and chalk which is inexpensive to manufacture, easy to use and which can be tethered to the top of the blackboard to prevent its being dropped or lost.

Other objects and advantages will become apparent in the following specification when considered in light of the attached drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the invention;

FIG. 2 is a vertical sectional view taken along the line 2-2 of FIG. I, looking in the direction of the arrows;

FIG. 3 is a top plan view of the invention; and

FIG. 4 is a perspective view of the eye member removed from the chalk.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail wherein like reference characters indicate like parts throughout the several Figures, reference numeral indicates generally a combined blackboard chalk and eraser constructed in accordance with the invention.

The combined blackboard chalk and eraser 10 includes a tapering chalk body 11 having a generally circular cross-section and being of a diameter substantially larger than that of standard chalk. The body 11 has an outer end 12 and an inner end 13 with the body tapering outwardly from the outer end 12 toward the inner end 13 so that the inner end 13 is substantially larger than the outer end 12.

A U-shaped metallic attaching element generally indicated at 14 includes a pair of spaced parallel arms l5, l6 integrally 10 joined by a bight 17. A right angle extension 18 is formed on each of the arms l5, 16 at the end thereof opposite the bight 17 to secure the attaching element 14 in the chalk body 11 with the bight 17 projecting therefrom to permit a string 19 to be detachably secured thereto.

A generally cylindrical eraser body 20 is secured to the inner end 13 of the chalk body 11 by casting the chalk against the eraser body 20 during the manufacture of the combined blackboard chalk and eraser 10. The eraser body 20 is formed of plastic foam or other porous or fibrous material. During the casting, the grains of chalk WlII pass through the lower face of the porous eraser body and will cause the eraser body to be bonded to the chalk body. While the casting of the chalk against the eraser body 20 is a preferred form of the invention, it should be understood that the eraser body 20 can be adhesively secured to the end 13 of the body 11 by any suitable gum or other adhesive material.

In the use and operation of the invention the string 19 is tied to the top of the blackboard and the chalk 10 is held in the hand with the end 12 presented'to the blackboard. When corrections are required a simple motion of the fingers causes the chalk to reverse and present the eraser body 20 to the blackboard so that the error may be erased. The porosity ,of the eraser body 20 is such that the chalk dust removed from the blackboard forms into small pellets which drop from the eraser body 20 in the form of chalk grains as the eraser is used. The string 19 may be made of an elastic material so that it can be stretched to reach any part of the blackboard in writing with the chalk of the instant invention.

While the chalk and eraser have been illustrated as having a circular cross-section, it should be understood that any desired cross-section may be used such as square, hexagonal, et cetera.

Having thus described the preferred embodiment of the invention, it should be understood that numerous structural modifications and adaptations may be resorted to without departing from the spirit of the invention.

What is claimed is:

1. A combined blackboard chalk and eraser comprising a porous plastic foam eraser body having opposed upper and lower faces and an elongate chalk body cast in contiguous relation with the lower face of said eraser body, with the grains of said chalk body passing through the lower face of said eraser body to bond said eraser body and chalk body together as a single unit. 

1. A combined blackboard chalk and eraser comprising a porous plastic foam eraser body having opposed upper and lower faces and an elongate chalk body cast in contiguous relation with the lower face of said eraser body, with the grains of said chalk body passing through the lower face of said eraser body to bond said eraser body and chalk body together as a single unit. 